While Microsoft has changed a lot of stuff, the keyboard commands in Windows and MS Office have remained mostly consistent in my experience, so when trying to work on someone else's computer, some things I could still figure out easily enough even though the system seems different. This could be done just as well in free software projects too (some of which already do, I think).

(However, for my own stuff, and on my own computer, I use neither MS Office nor LibreOffice nor other similar software, since I do not need them; I can use plain text, I can use TeX, I can use PostScript code (with Ghostscript), and whatever.)